﻿using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace T01WPF
{
    /// <summary>
    /// User数据库访问类：增、删、改、查等操作
    /// </summary>
    class UserDao
    {
        //MySQL的连接串描述
        private static string connStr
          = "server=localhost;user=root;password=;database=gametest";
        // 错误： private static string connStr
        //   = "sever=localhost;user=root;password=;database=test";

        /// <summary>
            /// 登录检查
            /// </summary>
            /// <param name="username">用户名</param>
            /// <param name="password">密码</param>
            /// <returns>0：无效 1：登录成功</returns>
        public static int LoginCheck(string username, string password)
        {
            //默认为无效用户名和密码
            int number = 0;
            //1.构建Mysql连接对象
            MySqlConnection conn = new MySqlConnection(connStr);

            try
            {
                //2.打开数据库链接
                conn.Open();
                //比较用户名与密码的SQL语句
                //string sql = "SELECT COUNT(id) FROM 'tb_users' WHERE 'username'='" + username + "'AND 'password'='" + "'";
                string sql = "SELECT COUNT(id) FROM `tb_users` WHERE `username`='"
                 + username + "' AND `password`='" + password + "'";

                Debug.WriteLine("SQL语句:" + sql);
                //3.创建SQL命令
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                //4.执行SQL命令
                object result = cmd.ExecuteScalar();
                if (result != null)
                {
                    number = Convert.ToInt32(result);
                }
            }
            catch (Exception ex)
            {

                Debug.WriteLine("数据库访问异常...");
                Debug.WriteLine("================");
                Debug.WriteLine(ex.ToString());
                Debug.WriteLine("================");
            }
            finally
            {
                if (conn != null)
                {
                    //5.关闭数据库连接
                    conn.Close();
                }
            }
           


            return number;
        }

        /// <summary>
        /// 获取所有用户列表
        /// </summary>
        /// <returns>用户列表集合</returns>
        public static List<User> LoadData()
        {
            //构建用户集合
            List<User> userList = new List<User>();

            MySqlConnection conn = new MySqlConnection(connStr);

            try
            {
                conn.Open();
                string sql = "SELECT * FROM tb_users";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                //3.获取数据访问的游标(当前记录)
                MySqlDataReader rdr = cmd.ExecuteReader();
                //4.依次访问数据记录并加入数据集合
                while (rdr.Read())
                {
                    User user = new User();
                    user.Id = Convert.ToInt64(rdr["id"]);
                    user.Username = Convert.ToString(rdr["username"]);
                    user.Password = Convert.ToString(rdr["password"]);
                    user.Nickname = Convert.ToString(rdr["nickname"]);
                    user.IsAdmin = Convert.ToInt16(rdr["is_admin"]) == 1 ? true : false;
                    userList.Add(user);
                }
                //5.关闭游标
                rdr.Close();
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.ToString());
            }
            finally
            {
                if (conn != null)
                    conn.Close();
            }

            //throw new NotImplementedException();
            return userList;
        }

        /// <summary>
        /// 按条件获取用户列表
        /// </summary>
        /// <param name="condition">条件参数值</param>
        /// <returns>符合条件的用户集合</returns>
        public static List<User> LoadData(string condition)
        {
            //构建用户集合
            List<User> userList = new List<User>();

            MySqlConnection conn = new MySqlConnection(connStr);

            try
            {
                conn.Open();
                //模糊查询
                string sql = "SELECT * FROM tb_users WHERE username LIKE @username OR nickname LIKE @nickname";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                //安全的参数（占位符）
                cmd.Parameters.AddWithValue("@username", "%" + condition + "%");
                cmd.Parameters.AddWithValue("@nickname", "%" + condition + "%");

                //3.获取数据访问的游标(当前记录)
                MySqlDataReader rdr = cmd.ExecuteReader();

                //4.依次访问数据记录并加入数据集合
                while (rdr.Read())
                {
                    User user = new User();
                    user.Id = Convert.ToInt64(rdr["id"]);
                    user.Username = Convert.ToString(rdr["username"]);
                    user.Password = Convert.ToString(rdr["password"]);
                    user.Nickname = Convert.ToString(rdr["nickname"]);
                    user.IsAdmin = Convert.ToInt16(rdr["is_admin"]) == 1 ? true : false;
                    userList.Add(user);
                }
                //5.关闭游标
                rdr.Close();
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.ToString());
            }
            finally
            {
                if (conn != null)
                    conn.Close();
            }

            //throw new NotImplementedException();
            return userList;
        }

        /// <summary>
        /// 新增用户
        /// </summary>
        /// <param name="user">用户数据实体</param>
        /// <returns>MySQL自增ID</returns>
        public static long Insert(User user)
        {
            long insertId = 0;

            MySqlConnection conn = new MySqlConnection(connStr);
            try
            {
                conn.Open();
                string sql = "INSERT INTO tb_users " + "(username,password,nickname,is_admin) " + "VALUES "
                    + "(@username,@password,@nickname,@is_admin) ";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                //参数绑定
                cmd.Parameters.AddWithValue("@username", user.Username);
                cmd.Parameters.AddWithValue("@password", user.Password);
                cmd.Parameters.AddWithValue("@nickname", user.Nickname);
                cmd.Parameters.AddWithValue("@id_admin", user.IsAdmin);
                cmd.ExecuteNonQuery();
                insertId = cmd.LastInsertedId;
            }
            catch (Exception ex)
            {

                Debug.WriteLine("数据插入异常" + ex.ToString());
            }
            finally
            {
                if (conn != null)
                {
                    conn.Close();
                }
            }

            return insertId;
        }

        /// <summary>
        /// 更新用户信息
        /// </summary>
        /// <param name="user">用户数据实体</param>
        public static void Update(User user)
        {
            MySqlConnection conn = new MySqlConnection(connStr);
            try
            {
                conn.Open();
                string sql = "UPDATE tb_users SET " + "username=@username, password=@password," +
                    "nickname=@nickname,is_admin=@is_admin " + "WHERE id=@id";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                //参数绑定
                cmd.Parameters.AddWithValue("@username", user.Username);
                cmd.Parameters.AddWithValue("@password", user.Password);
                cmd.Parameters.AddWithValue("@nickname", user.Nickname);
                cmd.Parameters.AddWithValue("@id_admin", user.IsAdmin);
                cmd.Parameters.AddWithValue("@id", user.Id);
                cmd.ExecuteNonQuery();            
            }
            catch (Exception ex)
            {

                Debug.WriteLine("数据更新异常" + ex.ToString());
            }
            finally
            {
                if (conn != null)
                {
                    conn.Close();
                }
            }
        }

        /// <summary>
        /// 删除用户信息
        /// </summary>
        /// <param name="id">删除用户的内部ID</param>
        public static void Delete(long id)
        {
            MySqlConnection conn = new MySqlConnection(connStr);
            try
            {
                conn.Open();
                string sql = "DELETE FROM tb_users WHERE id=@id";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@id", id);
                cmd.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                Debug.WriteLine("数据删除错误" + ex.ToString());
            }
            finally
            {
                if (conn != null)
                {
                    conn.Close();
                }
            }
        }
    }
}
